Spray devices for the application of liquids onto human skin and hair are well known. Sprays are used for many types of medicines, skin treatments, hair treatments, deodorants, lotions, and cosmetic agents. Specialized hand-held and automated spray systems have recently been introduced in tanning salons and spa treatment centers to apply sunless tanning compounds and skin care formulas, such as moisturizers, anti-aging treatments, and exfoliants. The spray solution used for sunless tanning is generally a water-based mixture of DHA (dihydroxyacetone) and/or erythrulose and various other skin care ingredients such as aloe vera. Often a cosmetic bronzer is added along with pleasant scents and ingredients to enhance tanning performance, such as formulations to balance skin ph. For best results, the spraying of the solution utilizes a finely atomized spray (mist), as opposed to the use of a spray stream or large spray droplets, because the mist of solution provides for even coverage and reduces the risk of streaking or running of the spray deposit.
The skin treatment spray process has inherently been a cold, uncomfortable experience for the recipient as nozzle expansion effects significantly cool the air and liquid in the spray cloud during application to the skin. Furthermore, cold skin is known to inhibit optimum absorption of the skin care ingredients. Temperatures of the spray cloud can be over 30 degrees (F) lower than human body temperature due to nozzle cooling and significantly cooler than ambient temperature (of the air or the liquid). Heating of the spray liquid or the atomization air has a negligible effect on increasing spray cloud temperature due to the rapid cooling produced as the spray jet expands when exiting the nozzle. This phenomenon is magnified when using air-atomizing nozzles; the type most desirable for producing a finely atomized spray mist.
In salons, customers disrobe for the spray treatment which lasts from 30 seconds to 5 minutes. Some treatments involve sequential spray regimens of alternate ingredients so the experience can be significantly longer. Thus, the length of time the customer is exposed to cold can be significant and may discourage the customer from obtaining the treatment in the first place or returning for an additional treatment at a later date.
After the spray treatment customers often use a towel to dry their skin. The action of toweling-off removes a significant quantity of the sprayed ingredients from the skin. The remaining ingredients may be redistributed, which can produce a splotchy appearance in the case of sunless tanning or other cosmetic treatments. If the customer opts not to use a towel, and instead simply dry off in the ambient air or from the cool air of air-atomizing nozzles, the surface of the skin can become sticky.
Many tanning salons providing the new sunless spray tanning service also have conventional UV lamp tanning beds. Customers have observed that application of sunless tanning solutions quickly after they use a UV tanning bed can result in a deeper and darker DHA tan. It is important to move from the UV tanning bed to receive a spray of sunless tanning solution as quickly as possible. It is also essential to remove all perspiration resulting from the UV treatment or the tan result can be uneven. The benefits of UV tanning coupled with a sunless tanning spray may be due to opening the pores of the skin and from more thoroughly and more deeply drying out of the top skin layer by the hot UV lamps. However, due to skin health concerns, many customers do not wish to use the UV beds and therefore cannot take advantage of this practice to enhance their sunless tan.
DHA tans the skin by reacting with proteins in the stratum corneum, the top protective skin layer composed of dead skin cells. It is known that only the uppermost dry layers of the stratum corneum will tan effectively with DHA or erythrulose. Very dry skin will pigment the darkest and layers containing surface moisture will not tan nearly as well. Skin care specialists suggest using a warm towel on the skin before application of spray treatments since warm skin may better absorb some ingredients. However, a skin surface that is too hot will perspire, thus reducing the effectiveness of the sprayed ingredients.
A need exists in the art to address the foregoing issues in connection with providing a better sunless tanning experience and result for the consumer.
Reference is further made to Venuto, U.S. Pat. No. 6,554,208 (the disclosure of which is hereby incorporated by reference) which teaches a tanning spray booth implementation with a nozzle operable to both spray tanning solution and deliver drying air when not spraying.
Reference is also made to Safara, U.S. Pat. No. 5,991,937 (the disclosure of which is hereby incorporated by reference) which teaches a bidet sprayer implementation operable to both spray cleaning water streams and deliver drying air when not spraying.